osfmk/vm/vm_external.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56 /*
  57  */
  58
  59 #ifndef VM_VM_EXTERNAL_H_
  60 #define VM_VM_EXTERNAL_H_
  61
  62 #include <mach/boolean.h>
  63 #include <mach/machine/vm_types.h>
  64
  65 /*
  66  *      External page management hint technology
  67  *
  68  *      The data structure exported by this module maintains
  69  *      a (potentially incomplete) map of the pages written
  70  *      to external storage for a range of virtual memory.
  71  */
  72
  73 typedef char    *vm_external_map_t;
  74 #define VM_EXTERNAL_NULL        ((char *) 0)
  75
  76 /*
  77  *      The states that may be recorded for a page of external storage.
  78  */
  79
  80 typedef int     vm_external_state_t;
  81 #define VM_EXTERNAL_STATE_EXISTS                1
  82 #define VM_EXTERNAL_STATE_UNKNOWN               2
  83 #define VM_EXTERNAL_STATE_ABSENT                3
  84
  85 /*
  86  * Useful macros
  87  */
  88 #define stob(s) ((atop_32((s)) + 07) >> 3)
  89
  90 /*
  91  *      Routines exported by this module.
  92  */
  93                                         /* Initialize the module */
  94 extern void                     vm_external_module_initialize(void);
  95
  96
  97 extern vm_external_map_t        vm_external_create(
  98                                         /* Create a vm_external_map_t */
  99                                         vm_offset_t             size);
 100
 101 extern void                     vm_external_destroy(
 102                                         /* Destroy one */
 103                                         vm_external_map_t       map,
 104                                         vm_size_t               size);
 105
 106 extern vm_size_t                vm_external_map_size(
 107                                         /* Return size of map in bytes */
 108                                         vm_offset_t     size);
 109
 110 extern void                     vm_external_copy(
 111                                         /* Copy one into another */
 112                                         vm_external_map_t       old_map,
 113                                         vm_size_t               old_size,
 114                                         vm_external_map_t       new_map);
 115
 116 extern void                     vm_external_state_set(
 117                                         /* Set state of a page to
 118                                          * VM_EXTERNAL_STATE_EXISTS */
 119                                         vm_external_map_t       map,
 120                                         vm_offset_t             offset);
 121
 122 extern void                     vm_external_state_clr(
 123                                         /* clear page state
 124                                          */
 125                                         vm_external_map_t       map,
 126                                         vm_offset_t             offset);
 127
 128 #define vm_external_state_get(map, offset)                              \
 129                         (((map) != VM_EXTERNAL_NULL) ?                  \
 130                           _vm_external_state_get((map), (offset)) :     \
 131                           VM_EXTERNAL_STATE_UNKNOWN)
 132                                         /* Retrieve the state for a
 133                                          * given page, if known.  */
 134
 135 extern vm_external_state_t      _vm_external_state_get(
 136                                         /* HIDDEN routine */
 137                                         vm_external_map_t       map,
 138                                         vm_offset_t             offset);
 139
 140 boolean_t                       vm_external_within(
 141                                         /* Check if new object size
 142                                          * fits in current map */
 143                                         vm_size_t       new_size,
 144                                         vm_size_t       old_size);
 145 #endif  /* VM_VM_EXTERNAL_H_ */